The Air-to-Ground path loss model presented in [1]} is not appropriate when we consider wireless coverage for indoor users, because this model assumes that all users are outdoor and located at 2D points. In this paper, we adopt the Outdoor-Indoor path loss model, certified by the ITU [2]}. The path loss is given as follows:
\(\begin{split}L_i=L_{F}+L_{B}+L_{I}= ~~~~~~~~~~~~~~~~\\(w\log _{10}d_{3D,i}+w\log _{10}f_{Ghz}+g_{1})+\\(g_{2}+g_{3}(1-\cos \theta _{i})^{2})+(g_{4}d_{2D,i})~~~~\end{split}\) 
